1. Technical Field
The present invention relates to a toner for electrostatic charge image development.
2. Description of Related Arts
It has recently been required to reduce heat energy at the time when a toner image is fixed, for the purpose of acceleration of a printing speed, reduction of environmental burden, or the like.
In order to reduce the heat energy at the time when the toner image is fixed, as described above, a technique capable of improving a low temperature fixability of a toner is required. One of methods for achieving is a method in which a crystalline resin such as crystalline polyester having excellent sharp meltability is used as a binder resin.
For example, JP-A-2006-251564 (corresponds to US 2006/204880 A1) proposes a toner for electrostatic charge image development which includes a binder resin containing a crystalline polyester resin and an amorphous resin. When the combination of the crystalline polyester resin and the amorphous resin is used as above, parts of crystals melt at a temperature over a melting point of the crystalline polyester resin in a temperature history on fixing to compatibilize the crystalline polyester resin with the amorphous resin; as a result, fixation can be attained at a lower temperature. According to JP-A-2006-251564 (corresponds to US 2006/204880 A1), it is also possible to cause the fixation at a temperature lower than that in conventional techniques by controlling thermal properties of the crystalline polyester resin and the amorphous resin contained in the binder resin to specific ranges.
WO 2006/135041 (corresponds to US 2009/068578 A1) and JP-A-2011-197659 (corresponds to US 2011/212398 A1) also disclose techniques using a crystalline resin such as a crystalline polyester as a binder resin. WO 2006/135041 (corresponds to US-A-2009/068578) proposes a binder resin for a toner, containing a hybrid resin, which is a copolymer of a crystalline polyester resin and an amorphous resin, and an amorphous resin. The binder resin for the toner described above has a phase-separated structure (sea-island structure) wherein the hybrid resin forms a matrix and the amorphous resin forms domains, which is excellent in the low temperature fixability. JP-A-2011-197659 (corresponds to US 2011/212398 A1) discloses a toner which is rendered to be fixed at a lower temperature by the introduction of a crystalline polyester resin to a binder resin containing a vinyl-based resin.